[Bio 11] Anatomy - Muscle Origin, Insertion, Action

Concentric Contraction

muscle is shortening

Eccentric Contraction

muscle is lengthening

Trapezius Origin

occipital bone, C7, thoracic vertebrae

Trapezius Insertion

clavicle, scapular spine and acromion

Trapezius Action

extends head -- elevates, depresses, rotates, retracts scapula

Latissimus Dorsi Origin

lower 6 thoracic, all lumbar vertebrae, iliac crest

Latissimus Dorsi Insertion

intertubercular groove (sulcus) of humerus

Latissimus Dorsi Action

extends, adducts, and medially rotates arm

Supraspinatus Origin

supraspinous fossa of scapula

Supraspinatus Insertion

greater tubercle of humerus

Supraspinatus Action

abducts and stabilizes humerus

Infraspinatus Origin

infraspinous fossa of scapula

Infraspinatus Insertion

greater tubercle of humerus

Infraspinatus Action

abducts and stabilzies humerus

Infraspinatus Synergist

teres minor

Subscapularis Origin

subscapular fossa of scapula

Subscapularis Insertion

lesser tubercle of humerus

Subscapularis Action

medially rotates and stabilizes shoulder

Rhomboids (Major + Minor) Origin

spinous process of C7 - T5

Rhomboids (Major + Minor) Insertion

medial border of scapula

Rhomboids (Major + Minor) Action

stabilizes scapula -- retracts and rotates downward

Teres Major Origin

inferior angle of scapula

Teres Major Insertion

lesser tubercle of humerus

Teres Major Action

synergist to latissimus dorsi

HUMAN Teres Minor Origin

lateral border of scapula

HUMAN Teres Minor Insertion

greater tubercle of humerus

HUMAN Teres Minor Action

synergist to infraspinatus

Erector Spinae

iliocostalis, longissimus, spinalis

Erector Spinatus Antagonist

abdominal muscles

Erector Spinatus Action

prime mover of back extensions (extends at back thigh)

Pectoralis Major Origin

clavicle, sternum, costal cartilages

Pectoralis Major Insertion

greater tubercle of humerus

Pectoralis Major Action

flexes, adducts, medially rotates arm

Pectoralis Minor Origin

ribs 3-5

Pectoralis Minor Insertion

coracoid process of scapula

Pectoralis Minor Action

draws scapula anterior and inferior

Serratus Anterior Origin

ribs 1-8

Serratus Anterior Insertion

medial border of scapula

Serratus Anterior Action

protracts and rotates scapula superiorly and laterally

External Intercostals Action

elevates ribs for inspiration

Internal Intercostals Action

depresses ribs for forced expiration

External Oblique Origin

lower 8 ribs

External Oblique Insertion

iliac crest, pubic crest, linea alba

External Oblique Action

flexes and rotates trunk

Internal Oblique Origin

lumbar fascia, inguinal ligament, iliac crest

Internal Oblique Insertion

lower 4 ribs, pubic crest, linea alba

Internal Oblique Action

flexes and rotates trunk

Transverse Abdominis Origin

iliac crest, cartilage of lower 6 ribs

Transverse Abdominis Insertion

linea alba, pubic crest

Transverse Abdominis Action

compresses abdomen

Rectus Abdominis Origin

pubic crest and pubic symphysis

Rectus Abdominis Insertion

costal cartilage of ribs 5,6,7 + xiphoid process

Rectus Abdominis Action

flexes and rotates trunk

Diaphragm

innervated by phrenic nerve from C3, C4, C5.

Diaphragm Origin

cartilages of lowest ribs, lumbar vertebrae

Diaphragm Insertion

central tendon

Diaphragm Action

prime mover of inspiration

Deltoid Origin

clavicle, acromion, scapular spine

Deltoid Insertion

deltoid tuberosity of humerus

Deltoid Action

abducts arm

Biceps Brachii Origin

coracoid process, supraglenoid tubercle

Biceps Brachii Insertion

radial tuberosity

Biceps Brachii Action

flexes and supinates forearm

Brachialis Origin

anterior, distal humerus

Brachialis Insertion

coronoid process of ulna

Brachialis Action

flexes forearm

Antagonist to Biceps Brachii

triceps brachii

Triceps Brachii Origin

infraglenoid tubercle, posterior humerus

Triceps Brachii Insertion

olecranon process

Triceps Brachii Action

extends forearm

Flexor Carpi Ulnaris Origin

medial epicondyle of humerus

Flexor Carpi Ulnaris Insertion

pisiform, hamate, metacarpal 5

Flexor Carpi Ulnaris Action

flexes wrist, adducts hand

Palmaris Longus Origin

medial epicondyle of humerus

Palmaris Longus Insertion

palmar aponeurosis

Palmaris Longus Action

wrist flexion

Flexor Carpi Radialis Origin

medial epicondyle of humerus

Flexor Carpi Radialis Insertion

metacarpal 2 and 3

Flexor Carpi Radialis Action

Flexes wrist, abducts hand

Pronator Teres Origin

medial epicondyle of humerus

Pronator Teres Insertion

lateral radius

Pronator Teres Action

pronates and flexes forearm

Brachioradialis Origin

lateral supracondylar ridge of humerus

Brachioradialis Insertion

styloid process of radius

Brachioradialis Action

flexes forearm

Extensor Carpi Ulnaris Origin

lateral epicondyle of humerus

Extensor Carpi Ulnaris Insertion

metacarpal 5

Extensor Carpi Ulnaris Action

extends wrist, adducts hand

Extensor Digitorum Minimi Origin

lateral epicondyle

Extensor Digitorum Minimi Insertion

distal phalange 5

Extensor Digitorum Minimi Action

extends 5th digit

Extensor Digitorum (Communis) Origin

lateral epicondyle

Extensor Digitorum (Communis) Insertion

distal phalanges 2-5

Extensor Digitorum (Communis) Action

extends wrists and fingers, abducts fingers

Extensor Carpi Radialis (longus + brevis) Origin

lateral epicondyle and lateral supracondylar ridge of humerus

Extensor Carpi Radialis (longus + brevis) Insertion

metacarpals 2 + 3

Extensor Carpi Radialis (longus + brevis) Action

extends wrist, abducts hand

Extensor Pollicis (longus + brevis) Action

extends thumb

Abductor Pollicus Longus Action

abducts and extends thumb

Sternocleidomastoid Origin

manubrium and clavicle